Last week, I watched the first episode of "Ripper Street" on BBC America. (It was very good, by the way.)

That prompted me to wonder what it is about Jack the Ripper that so captures our imaginations and encourages storytellers to feature him in tale after tale.

I’m not just talking about straight-up mystery and crime writers, either. Jack is a big deal in the genre of the fantastic. Just to mention a few of his appearances, he turned up in episodes of "Star Trek," "Babylon 5" and "Sanctuary," as well as in the "Dark Shadows/Vampirella" miniseries from Dynamite Comics. Why is that?

In part, Jack’s popularity is just one manifestation of our interest in serial killers in general, who impress us as the closest thing to pure evil running loose in the real world. By any objective standard, tyrants like Hitler and Stalin do a lot more damage, ordering the deaths of millions, but the political and ideological goals of the slaughter make it somewhat comprehensible though no less abominable.

Whereas serial murderers have no comparable objectives. When they kill, it’s for purely personal reasons, which makes them windows into the darkest, maddest potentialities of the human mind. If you’ve ever experienced a crazy, destructive impulse, or wondered even momentarily if you were going crazy, you likely have enough morbid curiosity to take a look inside.

Still, why the Ripper in particular? Criminologists differ on how many women he murdered, but five is the most common estimate. Peter Kurten (the Vampire of Dusseldorf) and Dennis Rader (the BTK Killer) killed more. John Wayne Gacy (the Clown Killer) and Gary Ridgway (the Green River Killer) killed many more. So how come none of them got to be on “Star Trek” in one of its incarnations? Are we more interested in Jack simply because he predates the others and so ranks as the patriarch of his diabolical clan? (He wasn’t really the first serial killer, but we tend to think of him that way because none before him triggered quite the same sort of media frenzy.)

The fact that Jack (kind of) came first is part of it, but there’s more involved. The Ripper wrote taunting letters to the police. Or maybe he did. Their authenticity is still a matter of debate. But if we assume they were real, the messages suggest a cool, confident game player, a real-world kindred spirit to the Joker or Raoul Silva (from "Skyfall"), and such villains can be hugely entertaining in fiction. (Obviously, they’d be less of a treat running amok in real life.)

Jack also intrigues us because his Victorian Age still does. The smug, self-righteous aristocrats with their hosts of servants, the wretched poor, and the sexual repression and licentious underground that existed alongside it both appall us and inspire an irrational nostalgia. And the Ripper’s career illuminated many of the less savory parts of his milieu.

By murdering prostitutes in Whitechapel, the poorest part of London, he drew attention to realities that many comfortable Englishmen had ignored, while the widely held belief that he must be a Jew or an immigrant revealed the prejudice of the time.

We also like Victorian London because so many great fictional characters inhabit it or can be shown visiting, and storytellers frequently hit on the idea of involving such icons in the Ripper case. "Murder by Decree" is probably still the most famous Sherlock Holmes versus Jack the Ripper tale, but there are many others. "Dr. Jekyll and Sister Hyde" posited that the unfortunate scientist’s alter ego (in this version, female) was the Ripper. (It threw in those other real-life murderers William Burke and William Hare, too, in a veritable 19th Century smorgasbord of skullduggery, blithely disregarding the fact that they did their killing in Edinburgh 60 years before Jack.)

Audiences enjoy these mash-ups. Otherwise, we wouldn’t keep getting them. In fact, their popularity is such that if "Downton Abbey" wants to maintain its ratings dominance in Season 4, I recommend that an aging (but still peppy and motivated) Ripper call at the estate. (Call me, Julian Fellowes!)

Anyway, each such story raises Jack’s profile and makes it more likely he’ll turn up in still more tales. But I think there’s an even greater reason for his appeal than any of the ones I’ve mentioned so far: Despite the best efforts of Scotland Yard and the Whitechapel Vigilance Committee, he was never caught, and people debate his true identity even today.

Ripperologists have advanced more than 100 suspects, including Sir William Gull (Queen Victoria’s physician-in-ordinary) and the Duke of Clarence (her grandson), and someone publishes a new book arguing a pet theory every couple years. Mysteries are inherently intriguing, and the fact that no one knows who the Ripper was gives storytellers the freedom to portray and dispose of him however they see fit.

Of course, it remains an open question whether real life ever disposed of him. If any of dozens of science-fiction and horror storytellers are right, and he at some point crossed paths with a vampire, encountered extraterrestrial visitors, stumbled on an elixir of immortality, or rose from the grave as a malevolent spirit, he could still be lurking around today.

So enjoy his many star turns in the genre of the fantastic, but be careful walking down foggy Whitechapel alleyways late at night.

About the Author

Richard Lee Byers is the author of more than 30 fantasy and horror novels, including a number set in the Forgotten Realms universe. Look for his eBook supehero series The Impostor, his eBook collection The Q Word and Other Stories, and all the rest of his work on Amazon, and Barnes & Noble. Follow him on Twitter (@rleebyers), friend him on Facebook, and add him to your Circles on Google+. Follow his blog here.